This invention relates to an ignition control system for an internal combustion engine for a vehicle and a method for controlling the ignition, and more particularly to an ignition control system adapted to control the ignition position of an internal combustion engine for a vehicle depending upon the engine speed of the internal combustion engine and a method for controlling the the same.
There has been recently developed an ignition system for an internal combustion engine for a vehicle which is adapted to control the ignition position of the internal combustion engine depending upon the engine speed of the engine using a micro computer. In such a conventional ignition control system, the ignition characteristics of the internal combustion engine which are characteristics of the ignition position of the engine with respect to the engine speed are generally determined irrespective of the gear position of a gear transmission. In other words, the conventional ignition control system is not adapted to vary the ignition characteristics of the engine depending upon the gear position.
However, actually, the desired ignition characteristics of the internal combustion engine are varied depending upon the gear position. More particularly, for example, when the gear of the gear transmission is changed over to a first gear position or low gear position, the internal combustion engine is increased in load as compared with the case that the gear is at a neutral position. This causes knocking to occur when the ignition position of the internal combustion engine excessively advances, leading to the fear that the engine is damaged. Thus, it is required to restrict the amount of advance of the ignition position when the gear is at the first gear position. Also, the changing-over of the gear to a maximum speed position causes the engine to be decreased in load, accordingly, delay of the ignition position at this time leads to a decreased in output of the engine.
The ignition characteristics of the conventional ignition control system, as described above, are rendered constant irrespective of the gear position of the gear transmission, so that the ignition characteristics are obliged to be set in view of a point of compromise. Thus, the conventional ignition control system fails to provide the ignition characteristics of the internal combustion engine optimum for each of the respective gear positions.